Engineering of Exciton-Plasmon Coupling Using 2D-WS2 Nanosheets for 1000-Fold Fluorescence Enhancement in Surface Plasmon-Coupled Emission Platforms.

Enhancement of fluorescence emission from single-photon quantum emitters on plasmonic nanomaterials using surface plasmon-coupled emission (SPCE) platforms has seen significant advancements. In parallel, there has also been an exponential rise in applications involving two-dimensional (2D) transition-metal dichalcogenides (TMDs) that exhibit unique exciton-plasmon interactions. Although both these Frontier research areas have impacted the development of sensor and sensing technologies, no study coalesces these two arenas for translational applications. In this work, we use thin WS2 nanosheets for realizing 1000-fold fluorescence enhancement on the SPCE platform. Structure-dependent fluorescence enhancement exhibited by WS2 provides new insight into the use of TMDs and exciton-plasmon coupling in SPCE substrates. Cellphone-based detection of the emitting dipole is another unique aspect of this work that presents a low-cost alternative in comparison with high-end detectors.